Implement new create and manager trigger UI

Implements the new trigger setup user interface, which is now a linear workflow found on its own page, rather than a tiny modal dialog

Fixes #1187

data/model/user.py

@@ -328,6 +328,11 @@ def delete_robot(robot_username):
                                 robot_username)
 
 
+def list_namespace_robots(namespace):
+  """ Returns all the robots found under the given namespace. """
+  return _list_entity_robots(namespace)
+
+
 def _list_entity_robots(entity_name):
   """ Return the list of robots for the specified entity. This MUST return a query, not a
       materialized list so that callers can use db_for_update.